Actually cloudy water is a sign that a form of less than beneficial bacteria is trying to develop in the tank. A larger water change is always a good idea if you notice something out of the ordinary is going on in your tank. The best thing for your tank is removing and replacing half the water weekly. This will maintain a steady and healthy environment for your fish. It takes several days for waste material to begin to build to a toxic level in the water. By changing half weekly, you remove toxins before they build up and you save time by not getting out the gear to change the water more than once a week.
"Fear not, my young apprentice. Just change the tank water."